Concrete pump assembly

ABSTRACT

Concrete pump assembly regulated by control flap valves with two pump cylinders and a common outlet opening. On two sides of the outlet opening in a control housing is a pair of control flap valves, which are rockable about their axes and alternately connect one of the two pump cylinders with the outlet opening and at the same time connect the other pump cylinder with a suction opening.

United States Patent [72] lnventor Friedrich Schwing Rathausstrasse 126,468 Wanne-Eickel, Germany [21] Appl. No. 817,480 [22] Filed Apr. 18,1969 [45] Patented May 25, 1971 [54] CONCRETE PUMP ASSEMBLY 1 Claim, 2Drawing Figs.

[52] [1.8. CI 417/515, 417/532, 417/900 [51] Int. Cl F04b 1/00, F04b21/02, F04b 15/02 [50] Field of Search 103/169, 170, 227, 228; 417/317,531, 532, 515, 900

[56] References Cited UNITED STATES PATENTS 2,548,733 4/1951 Longenecker417/900 Primary Examiner-Henry F. Raduazo Attorney-Malcolm W. FraserABSTRACT: Concrete pump assembly regulated by control flap valves withtwo pump cylinders and a common outlet opening. On two sides of theoutlet opening in a control housing is a pair of control flap valves,which are rockable about their axes and alternately connect one of thetwo pump cylinders with the outlet opening and at the same time connectthe other pump cylinder with a suction opening.

CONCRETE PUMP ASSEMBLY BACKGROUND OF THE INVENTION With the concretepumps today predominantly carried out with two pump cylinders, differentcontrol systems are utilized. One of the usual ways is to employ flatslide valves, which by means of hydraulic cylinders are pressed intochannels of the control housing and are drawn out again. This technicalsolution has the disadvantage of a rather high wear, as well asappreciable packing problems, because flat slide valves must be guidedon rods which lead outwardly, where they are connected by cross tie rodsagainst which the hydraulic cylinders operate. The sealing of thereciprocating guide rods becomes more difficult if the latter throughwear have lost their uniform round cross section. Since these pumps havetwo outlet apertures, the necessity additionally exists of employing acollecting pipe joining the two outer channels.

Additionally, flat slide valves appeared more favorable than rotaryvalves used predominatingly earlier, which can be sealed more easily,because they have a particularly high degree of wear and because in thevicinity of their end posi tions they act as stone-crushers. On accountof the large surfaces which are under pressure, great friction momentsmust be overcome upon their movement, particularly at high pressures inthe conveyor conduit.

Another type of construction utilizes a two-armed valve which, in itsend positions, separates one pump cylinder from the other, and connectsone cylinder with the outlet aperture, the other with a suction openinglying between the two pump cylinders. This type of construction has theadvantage that the packing towards the outside is simple, because it isa matter of sealing the rotating movements of thin pins. The furtheradvantage is the small size of the surfaces causing friction.

The disadvantages of this type of construction lie in the particularlyunfavorable flow conditions, which results in frequent plugging up ofthe control housing. The diameter of the suction aperture which liesbetween the two pump cylinders, determines the size of the deflection ofthe feed stream on the path from the end of the pump cylinder to theoutlet aperture of the control housing. On this account a relativelysmall suction aperture must be utilized. Upon the suction operation,the'concrete is additionally deflected at least 180.

I SUMMARY OF THE INVENTION The invention has the object of overcomingthe disadvantages of the last-described type of construction withrespect to the unfavorable flow conditions, both as to the suction sideas well as to the pressure side in the control housing.

This problem is solved according to the invention in this way, that ontwo sides of the outlet opening flaps or valves are positioned swingableabout axes parallel to one another, which in their two end positionsalternately connect one of the two pump cylinders with the outletopening and at the same time the other pump cylinder with the suctionopening correlated to it.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a sectional viewsubstantially on the line l-l of FIG. 2 showing a control housingaccording to the invention, and two pump cylinders ofa concrete pump;and

FIG. 2 is a longitudinal sectional view substantially on the line 2-2 ofFIG. 1 showing a pump cylinder and the control housing according to theinvention.

DESCRIPTION OF PREFERRED EMBODIMENT A pair of spaced cylinders l and 2contain reciprocating feed pistons 3 and 4 respectively, the piston 3being shown performing its pressure or feed stroke and the piston 4being shown performing its suction stroke, as indicated by therespective arrows. The cylinders l and 2 are suitably connected to acontrol housing 5 and register with oppositely inclined passages 1 and 2respectively, which converge and connect to an outlet passage 8 whichcommunicates with an outlet pipe 8 suitably connected to the housing 5.Extending laterally from the passages 1 and 2' are suction passages 9and 10 respectively, which communicate with pipes (not shown) leadingfrom the source'of concrete.

Within the housing 5 adjacent the mouth of the outlet passage 8 and onopposite sides thereof are rockable or swingable valve flaps 6 and 7.The valve flap 6 controls the passages l and 9 and the valve flap 7controls the passages 2' and 10 depending upon their positions ofadjustment. The free end of each of the valve flaps is pointed toprovide flat surfaces to engage flatwise against the walls of theinclined passages or suction passages depending upon the respectivepositions thereof.

Each of the valve flaps 6 and 7 is fixed to oscillatable pins C and Drespectively, which have bearing in the control housing 5. One end ofeach of the pins projects outside of the housing to receive an operatingarm which is keyed to the respective pin. One of the arms designated as11 is shown on FIG. 2, but it will be understood that a similar arm issecured to the extending portion of the pin C. i

The arms for operating the valve flaps 6 and 7 are driven in anysuitable manner so that one of the valve flaps is in a posienable thepiston 4 to draw concrete in to the control housing and at the same timeto close off communication between the inclined passage 2' and theoutlet passage 8. At the same time the valve flap 6 is rocked to thefull line position of FIG. 1, closing ofi the suction opening 9 anduncovering the inclined passage 1 and enabling the piston 3 to forceconcrete from the housing 5 through the inclined passage 1, the outletpassage 8 and into the outlet pipe 8'. When the pistons 3 and4 reversethe movements shown by the arrows on FIG. I, then the valve flaps 6 and7 are abruptly rocked to the broken line positions of FIG. I when thepiston 4 operates to force concrete from the housing 5 and the piston 3draws or sucks concrete into the housing. Of course, the actionabovedescribed continues throughout the pumping operation, as will bereadily understood.

Iclaim:

l. A pump assembly for handling concrete comprising a housing, I

a pair of closely arranged passages disposed wholly within said housingand converging from one side to an intermediate portion within saidhousing,

an outlet passage within said housing and leading from said intermediateportion with the axis thereof disposed between said converging passagesand extending from the side of said housing opposite to saidfirst-mentioned side,

a pair of pump cylinders in closely spaced parallel relation on theouter side of said housing and communicating with the outer ends of saidconverging passages respectively,

pistons reciprocable respectively in said cylinders for operatingconcomitantly in opposite directions,

a pair of laterally disposed inlet passages arranged on opposite sidesof and wholly within said housing and communicating directly with saidintermediate portion for supplying concrete to said converging passagesrespectively, the inner ends of said lateral passages being juxtaposedto the inner end of said outlet passage and the inner ends of saidconverging passages,

a pair of oscillatable pins mounted in said housing, one being arrangedon each side of said outlet passage and disposed in parallel relation,

a flap valve mounted on each pin for oscillating movement therewith,

said flap valves being so arranged that in one position one valve closesthe adjacent inlet passage and uncovers. said outlet passage, therebyenablingthe piston on that side of the housing to force concrete fromthe respective cylinder through said intermediate portion and outthrough said outlet passage, and at the same time enabling the othervalve to uncover the inlet passage adjacent thereto, thereby enablingthe piston on that side of last valve in such position closing off thepassage of the said outlet passage, and

the housing to draw or suck concrete through the admeans for oscillating531d pins.

jacent inlet passage and into the respective cylinder, said

1. A pump assembly for handling concrete comprising a housing, a pair ofclosely arranged passages disposed wholly within said housing andconverging from one side to an intermediate portion within said housing,an outlet passage within said housing and leading from said intermediateportion with the axis thereof disposed between said converging passagesand extending from the side of said housing opposite to saidfirst-mentioned side, a pair of pump cylinders in closely spacedparallel relation on the outer side of said housing and communicatingwith the outer ends of said converging passages respectively, pistonsreciprocable respectively in said cylinders for operating concomitantlyin opposite directions, a pair of laterally disposed inlet passagEsarranged on opposite sides of and wholly within said housing andcommunicating directly with said intermediate portion for supplyingconcrete to said converging passages respectively, the inner ends ofsaid lateral passages being juxtaposed to the inner end of said outletpassage and the inner ends of said converging passages, a pair ofoscillatable pins mounted in said housing, one being arranged on eachside of said outlet passage and disposed in parallel relation, a flapvalve mounted on each pin for oscillating movement therewith, said flapvalves being so arranged that in one position one valve closes theadjacent inlet passage and uncovers said outlet passage, therebyenabling the piston on that side of the housing to force concrete fromthe respective cylinder through said intermediate portion and outthrough said outlet passage, and at the same time enabling the othervalve to uncover the inlet passage adjacent thereto, thereby enablingthe piston on that side of the housing to draw or suck concrete throughthe adjacent inlet passage and into the respective cylinder, said lastvalve in such position closing off the passage of the said outletpassage, and means for oscillating said pins.